中文摘要：

多层界面效应和声阻抗差异造成超声传播复杂及回波信号衰减,为增强回波信号强度提高多层构件的超声自动检测质量,基于多元高斯声束理论,建立了脉冲激励方式下超声波在多层构件内的传播模型及测量模型,并基于此模型研究了多层构件水浸自动超声检测时的水声距优化方法,并以铝-黄铜粘接件水浸探伤为例进行了应用研究。仿真及实验结果表明该方法可有效获取最优水声距,显著增加了粘接层回波幅值,由此提高信噪比和缺陷分辨率,为改善复杂构件的自动超声检测提供参考。

英文摘要：

Multilayer interface effects and their acoustic impedance differences lead to the complexity of ultrasonic propagation and great attenuation of echo waves.To increase the intensity of echo signal and improve the quality of automatic ultrasonic inspection for multilayer components,the pulse excitation ultrasonic propagation model and the measurement model for multilayer components based on the multi-Gaussian beam theory were established.Based on these models,the water path length optimization method in automatic immersion ultrasonic testing for multilayer components was studied.As an example of the application,the immersion ultrasonic inspection of an aluminum-brass adhesive component was studied.Simulation and experiment results show that the proposed method can effectively obtain optimal water path length,obviously increase the adhesive layer echo amplitude,which improves the signal noise ratio and defect resolution; so this method can act as a useful tool for automatic ultrasonic inspection of complex components.